The present invention relates to an apparatus and a method for the sterilization of containers. Apparatus and methods of this type have long been known from the prior art. Attempts have been made in recent years to dispense with the possibility of using chemical sterilization agents or at least to reduce this use. In recent years sterilization devices have also been known which act upon the walls of the containers to be sterilized with a radiation, and in particular a charge carrier radiation. The present invention is described essentially with reference to radiators of electrons, but it should be pointed out that an application of the invention is also optionally possible in the case of other charge carriers, such as for example protons or alpha particles. In addition, other types of radiation, such as x-rays or UV radiation, could also be used.
Apparatus and methods are known from the prior art in which radiation fingers are inserted—by way of the apertures of the containers to be sterilized—into the aforesaid containers. These radiation fingers usually have in this case an outlet window for charge carriers, such as in particular electrons. It is advantageous in this case for the outlet window to be arranged on an underside of the respective radiation fingers. On the one hand these radiation fingers must have in this case a cross-section which is capable of being inserted into the container through the aperture. On the other hand these radiation fingers must usually also maintain in the interior thereof a vacuum inside which the charge carriers can be accelerated. This leads to radiation fingers of this type frequently being very delicate and also expensive appliances. On account of the low mechanical loading capacity the costs in the event of one-off light or even severe damage are also very high.
Furthermore, sterilization devices which use radiation, and in particular electron beams, for sterilization purposes usually have an electron production device, and also an acceleration device which accelerates the charge carriers (in particular inside a/the vacuum) in the direction of the outlet window.
In the same way, apparatus are known from the prior art in which the sterilization devices are arranged on a movable carousel. In addition, the containers and, in particular, pre-forms are arranged on a movable carousel by way of clamps. For the internal sterilization each individual container is moved on the clamps by way of the sterilization device or the radiation finger associated with the sterilization devices respectively. In this case an electric motor, which handles a drive profile individually during the treatment cycle, is available in each case (for example on the carousel) in order to produce the movement of the respective clamp.
A drawback in the case of the prior art, however, is that linear motors are very expensive and the outlay of the control and programming (for example in order to produce the drive profile) is enormous, but no mechanical parts have to be changed in the event of a change in format of the containers.
The object of the present invention is therefore to overcome these drawbacks and to provide an apparatus as well as a method, which at the same time is capable of being used or modified respectively in an inexpensive and nevertheless flexible manner and can be used for the sterilization of widely differing formats of containers.
In this case, however, the aperture of the container should remain substantially the same or should at least have a certain minimum cross-section, since the rod-like body or radiation finger respectively must be capable of still being guided securely in the container, so that containers of different lengths and diameters can be sterilized in an inexpensive manner by the apparatus.